<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <script>
    'use strict';
    var arr = [3,4,5];
 /*   for (let i = 0; i < arr.length; i++) {
      console.log(arr[i]);
    }*/
    console.log("arrstart:")
    for(let x of arr){
      console.log(x);
    }

    console.log("setstart:")
    var set = new Set([1,1,2,34,5,63222,31,3]);
    for(let x of set){
      console.log(x);
    }

    var map = new Map([["tom",1],["jack",2],["hali",3]]);
    console.log("mapstart:")
    for(let x of map){
      console.log(x);
    }

    // 三维数组,一个里面专门放key，一个里面放value
    var map2 = new Map([[["v1","v2","v3"],[1,2,3]],[["vv1","vv2","vv3"],[1,2,3]],[["vvv1","vvv2","vvv3"],[1,2,3]]]);
    console.log("map2start:");

    for(let x of map2){
      console.log(x);
    }

  </script>
</head>
<body>

</body>
</html>